High-temperature deformation behavior in SrTiO3 ceramics
- Resource Type
- Article
- Authors
- Singh, D.; Lorenzo-Martín, M.; Chen, G.; Gutiérrez-Mora, F.; Routbort, J.L.
- Source
- Journal of the European Ceramic Society. Sep2007, Vol. 27 Issue 11, p3377-3384. 8p.
- Subject
- *DEFORMATIONS (Mechanics)
*POLYCRYSTALS
*STRONTIUM compounds
*CERAMICS
*STRAINS & stresses (Mechanics)
- Language
- ISSN
- 0955-2219
Abstract: The high-temperature deformation behavior of a polycrystalline strontium titanate (SrTiO3) ceramic (6μm grain size) was investigated at temperatures of 1200–1345°C in an argon atmosphere. Compressive deformation tests were conducted at strain rates ranging from 5×10−6 to 5×10−5 s−1. Steady-state flow stresses were 0.05–30MPa and increased with increasing strain rates. Stress exponents of ≈1, at temperatures >1200°C, indicated a viscous diffusion-controlled deformation with an activation energy of ≈628±24kJ/mol. Comparison of activation energy with literature data suggests diffusion of cations as the rate-controlling mechanism. Absence of cavitation and grain-shape changes were consistent with grain-boundary sliding as the principal deformation mechanism. The electron back-scattered diffraction (EBSD) technique was used to determine the grain orientation as a function of applied strain. The results indicate that some of the grains rotate with cumulative rotation as large as 7° at a strain of 4%. [Copyright &y& Elsevier]